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Locating Places on the Earth

Chapter 1. Locating Places on the Earth

This chapter explains how maps and globes help us locate places on the Earth. It also introduces coordinates, latitudes, longitudes, hemispheres, local time, standard time, time zones and the International Date Line.

Chapter Review

Introduction

• A map is a representation or drawing of an area of the Earth's surface viewed from above.
• Maps can represent a small area such as a village or town, a larger area such as a district or state, or a very large area such as India or the whole world.
• An atlas is a book or collection of maps.
• Physical maps mainly show natural features such as mountains, oceans and rivers.
• Political maps show countries, states, boundaries, cities and other political features.
• Thematic maps show a particular type of information about an area.
• The three important components of a map are distance, direction and symbols.
• Scale helps represent a large area on a small piece of paper by showing the relationship between map distance and actual ground distance.
• Cardinal directions are north, east, south and west.
• The intermediate directions are northeast, southeast, southwest and northwest.
• Symbols are used to represent different natural and human-made features on maps.
• The Survey of India has fixed a set of symbols for maps of India and parts of India.
• The Earth is nearly spherical and is slightly flattened at the poles.
• A globe is a spherical model on which a map of the Earth or another celestial body can be represented.
• A globe represents the Earth's spherical shape better than a flat map.
• A system of coordinates helps us determine the precise location of a place.
• Latitude and longitude together form the two coordinates of a place.
• Latitude measures the distance of a place north or south of the Equator.
• Parallels of latitude are imaginary circles that run east-west and are parallel to the Equator.
• The Equator is the largest parallel of latitude and represents 0° latitude.
• The latitude of the North Pole is 90°N and that of the South Pole is 90°S.
• Parallels of latitude become smaller as they move towards the North or South Pole.
• Latitude is related to climate; areas near the Equator are generally hot, while areas near the poles are much colder.
• Meridians of longitude are imaginary half-circles running from the North Pole to the South Pole.
• Longitude measures the distance of a place east or west of the Prime Meridian.
• The Prime Meridian is the 0° longitude and is also called the Greenwich Meridian.
• The Prime Meridian passes through Greenwich in London, England.
• Longitudes are measured eastward or westward from 0° to 180°.
• 180°E and 180°W represent the same longitude.
• Latitude and longitude together can be used to locate any place precisely on Earth.
• Parallels of latitude and meridians of longitude together form a grid of imaginary lines on the globe.
• The Equator divides the Earth into the Northern and Southern Hemispheres.
• The Prime Meridian divides the Earth into the Eastern and Western Hemispheres.
• Ancient Indian astronomers were familiar with latitude, longitude and the idea of a prime meridian.
• Ujjayini, present-day Ujjain, was an important centre of astronomy in ancient India.
• The Ujjayini meridian was called madhya rekhā or the “middle line”.
• The Ujjayini meridian was used as a reference for calculations in ancient Indian astronomical texts.
• Varāhamihira, a famous astronomer, lived and worked at Ujjayini about 1,500 years ago.
• India extends approximately from 8°N to 37°N latitudes and from 68°E to 97°E longitudes.
• The Earth rotates from west to east and completes one full rotation in 24 hours.
• A complete rotation of the Earth is 360°, so the Earth rotates through 15° of longitude in one hour.
• Local time changes with longitude.
• When we move eastward, local time becomes later.
• When we move westward, local time becomes earlier.
• At every 15° of longitude, there is approximately a one-hour difference in local time.
• If it is noon at the Prime Meridian, the local time is 1 pm at 15°E and 11 am at 15°W.
• Using local time separately for every place would be inconvenient for a country.
• Countries therefore adopt a standard time based on a selected meridian.
• India follows Indian Standard Time (IST).
• Indian Standard Time is 5 hours 30 minutes ahead of Greenwich Mean Time (GMT).
• Standard times are organised into time zones.
• Time zones broadly follow zones of 15° longitude.
• Time-zone boundaries are not always straight because they often follow international borders.
• Large countries may have several time zones.
• The USA has six time zones, while Russia has eleven time zones.
• The International Date Line lies approximately at 180° longitude, opposite the Prime Meridian.
• Crossing the International Date Line changes the date by one day.
• When the International Date Line is crossed eastward, one day is subtracted.
• When it is crossed westward, one day is added.
• The International Date Line is not exactly straight because it deviates in some places to avoid dividing countries into two different dates.

Important Definitions

Term	Definition
Map	A representation or drawing of an area of the Earth's surface viewed from above.
Atlas	A book or collection of maps.
Physical Map	A map that mainly shows natural features such as mountains, oceans and rivers.
Political Map	A map that shows countries, states, boundaries, cities and other political features.
Thematic Map	A map that shows a specific type of information about an area.
Scale	The relationship between a distance shown on a map and the actual distance on the ground.
Direction	The position of one place in relation to another place, such as north, south, east or west.
Symbol	A conventional sign used on a map to represent a particular feature.
Globe	A spherical model on which a map of the Earth or another celestial body can be represented.
Coordinates	Two values, latitude and longitude, used together to determine the precise location of a place.
Latitude	The measure of the distance of a place north or south of the Equator.
Parallel of Latitude	An imaginary circle running east-west and parallel to the Equator.
Equator	The 0° latitude that divides the Earth into the Northern and Southern Hemispheres.
Longitude	The measure of the distance of a place east or west of the Prime Meridian.
Meridian of Longitude	An imaginary half-circle running from the North Pole to the South Pole.
Prime Meridian	The 0° longitude passing through Greenwich in London.
Hemisphere	One half of the Earth.
Local Time	The time at a particular place determined according to its longitude.
Standard Time	The officially adopted time followed by a country or region.
Time Zone	A geographical region in which a particular standard time is followed.
Indian Standard Time (IST)	The standard time followed throughout India, which is 5 hours 30 minutes ahead of GMT.
Greenwich Mean Time (GMT)	The time at Greenwich used as a reference for comparing standard times.
International Date Line	An imaginary line located approximately at 180° longitude where crossing the line changes the date by one day.
Grid Lines	The network of latitudes and longitudes drawn on a globe or map to help locate places.

Important Terms

• Map
• Atlas
• Physical Map
• Political Map
• Thematic Map
• Scale
• Distance
• Direction
• Symbols
• Globe
• Coordinates
• Latitude
• Parallel of Latitude
• Equator
• Longitude
• Meridian
• Prime Meridian
• Greenwich Meridian
• Hemisphere
• Northern Hemisphere
• Southern Hemisphere
• Eastern Hemisphere
• Western Hemisphere
• Local Time
• Standard Time
• Time Zone
• Indian Standard Time (IST)
• Greenwich Mean Time (GMT)
• International Date Line
• Grid Lines
• Cardinal Directions
• Intermediate Directions
• madhya rekhā

Important Points

• The three main components of a map are distance, direction and symbols.
• The four cardinal directions are North, East, South and West.
• The four intermediate directions are Northeast, Southeast, Southwest and Northwest.
• A map may represent a village, town, district, state, country or the whole world.
• A physical map shows natural features.
• A political map shows political features such as countries, states and boundaries.
• A thematic map provides information about a particular theme.
• Scale makes it possible to represent a large area on a small map.
• For example, a scale of 1 cm = 500 m means that 1 cm on the map represents 500 m on the ground.
• Symbols allow many features to be represented in the limited space available on a map.
• The Survey of India has fixed a set of symbols for maps of India and parts of India.
• The Earth is nearly spherical and slightly flattened at the poles.
• A globe represents the spherical shape of the Earth better than a flat map.
• Coordinates are used to locate places precisely.
• Latitude is measured north or south of the Equator.
• Longitude is measured east or west of the Prime Meridian.
• The Equator is the longest parallel of latitude and is marked 0°.
• The North Pole is at 90°N and the South Pole is at 90°S.
• Parallels of latitude become smaller towards the poles.
• All meridians of longitude are half-circles extending from one pole to the other.
• The Prime Meridian is marked 0° longitude.
• Longitudes increase from 0° to 180° towards both east and west.
• 180°E and 180°W represent the same longitude.
• Latitude and longitude together form the coordinates of a place.
• The Equator divides the Earth into the Northern and Southern Hemispheres.
• The Prime Meridian divides the Earth into the Eastern and Western Hemispheres.
• The grid of latitudes and longitudes helps locate places accurately on Earth.
• Ancient Indian astronomers understood the concepts of latitude and longitude.
• The Ujjayini meridian, or madhya rekhā, was used as a reference in ancient Indian astronomy.
• India extends approximately from 8°N to 37°N latitudes.
• India extends approximately from 68°E to 97°E longitudes.
• The Earth completes one rotation through 360° in 24 hours.
• 15° of longitude corresponds approximately to 1 hour of time difference.
• Moving eastward increases local time.
• Moving westward decreases local time.
• India follows a single standard time known as Indian Standard Time (IST).
• IST is 5 hours 30 minutes ahead of GMT.
• Time zones broadly follow 15° zones of longitude.
• Time-zone boundaries may bend and follow international borders.
• The USA has six time zones and Russia has eleven time zones.
• The International Date Line lies approximately at 180° longitude.
• Crossing the International Date Line changes the date by one day.
• When crossing the International Date Line eastward, one day is subtracted.
• When crossing it westward, one day is added.

5-Minute Revision

• ✔ Map = Representation of an area of the Earth's surface.
• ✔ Atlas = Book or collection of maps.
• ✔ Main components of a map = Distance + Direction + Symbols.
• ✔ Main types of maps = Physical + Political + Thematic.
• ✔ Globe = Spherical model of the Earth.
• ✔ Coordinates = Latitude + Longitude.
• ✔ Equator = 0° latitude.
• ✔ North Pole = 90°N.
• ✔ South Pole = 90°S.
• ✔ Prime Meridian = 0° longitude.
• ✔ Latitude = Distance north or south of the Equator.
• ✔ Longitude = Distance east or west of the Prime Meridian.
• ✔ Equator → Northern + Southern Hemispheres.
• ✔ Prime Meridian → Eastern + Western Hemispheres.
• ✔ Latitude + Longitude → Exact location of a place.
• ✔ 15° longitude ≈ 1 hour time difference.
• ✔ East → Local time becomes later.
• ✔ West → Local time becomes earlier.
• ✔ IST = GMT + 5 hours 30 minutes.
• ✔ International Date Line ≈ 180° longitude.
• ✔ Crossing the International Date Line → Date changes by one day.

Exam Booster

• Learn the three main components of a map: distance, direction and symbols.
• Understand the difference between physical, political and thematic maps.
• Understand how scale is used to calculate actual distance from map distance.
• Remember all four cardinal and four intermediate directions.
• Know why symbols are necessary on maps.
• Understand why a globe represents the Earth more naturally than a flat map.
• Remember that latitude and longitude are the two coordinates of a place.
• Learn the difference between a parallel of latitude and a meridian of longitude.
• Remember the values of the Equator, North Pole, South Pole and Prime Meridian.
• Understand how the Equator and Prime Meridian divide the Earth into four hemispheres.
• Remember India's approximate latitudinal and longitudinal extent.
• Know the importance of the ancient Ujjayini meridian in Indian astronomy.
• Understand the relationship between longitude and local time.
• Remember the key relationship: 15° longitude = approximately 1 hour.
• Remember that local time becomes later towards the east and earlier towards the west.
• Understand the difference between local time and standard time.
• Remember that India's standard time is IST = GMT + 5:30.
• Understand why large countries may have multiple time zones.
• Remember the approximate location of the International Date Line.
• Understand why crossing the International Date Line changes the date by one day.
• For numerical questions, carefully use the relationship between longitude and time.

Locating Places on the Earth

Locating Places on the Earth

Page 2 Notes

1. Important Terms and Definitions

Map

A map is a representation or drawing of an area of the Earth's surface viewed from above.

Atlas

An atlas is a book or collection of maps.

Scale

Scale shows the relationship between the distance on a map and the actual distance on the ground.

Globe

A globe is a spherical model of the Earth.

Coordinates

Coordinates are values used to identify the precise location of a place on the Earth.

Latitude

Latitude is the measure of the distance of a place north or south of the Equator.

Longitude

Longitude is the measure of the distance of a place east or west of the Prime Meridian.

Equator

The Equator is the 0° latitude that divides the Earth into the Northern and Southern Hemispheres.

Prime Meridian

The Prime Meridian is the 0° longitude passing through Greenwich.

Local Time

Local time is the time of a particular place based on its longitude.

Standard Time

Standard time is the officially adopted time followed by a country or region.

Time Zone

A time zone is a region in which the same standard time is followed.

International Date Line

The International Date Line is an imaginary line located approximately at 180° longitude where crossing the line changes the date by one day.

2. Important Differences

Map	Globe
A map is a flat representation of the Earth's surface.	A globe is a spherical model of the Earth.
It can show a very small or very large area in detail.	It represents the Earth as a whole or in a spherical form.

Latitude	Longitude
Measures distance north or south of the Equator.	Measures distance east or west of the Prime Meridian.
Parallels run east-west.	Meridians run from pole to pole.
Equator is 0° latitude.	Prime Meridian is 0° longitude.

Local Time	Standard Time
It depends on the longitude of a particular place.	It is the officially adopted time of a country or region.
It can differ from one place to another.	It is kept uniform within the relevant region.

Parallel of Latitude	Meridian of Longitude
Runs east-west.	Runs from the North Pole to the South Pole.
Parallel to the Equator.	All meridians meet at the poles.
Equator is the longest parallel.	Prime Meridian is the reference meridian.

3. Topic-wise Notes

Topic 1: Maps

• A map represents an area of the Earth's surface.
• Maps are viewed as if the area is being seen from above.
• Maps can represent villages, towns, districts, states, countries or the whole world.
• An atlas is a collection of maps.

Topic 2: Types of Maps

• Physical Maps: Show natural features such as mountains, rivers and oceans.
• Political Maps: Show countries, states, boundaries and cities.
• Thematic Maps: Show information related to a particular theme.

Topic 3: Components of a Map

• The three main components of a map are distance, direction and symbols.
• Distance: Shows how far one place is from another.
• Direction: Helps us determine the position of one place in relation to another.
• Symbols: Represent different features on a map.

Topic 4: Scale

• Scale shows the relationship between map distance and actual ground distance.
• It allows large areas to be represented on small maps.
• For example, if 1 cm on a map represents 500 m on the ground, the scale is 1 cm = 500 m.

Topic 5: Directions

• The four cardinal directions are North, East, South and West.
• The intermediate directions are Northeast, Southeast, Southwest and Northwest.
• Directions help us locate one place in relation to another.

Topic 6: Symbols

• Maps use symbols to represent different features.
• Symbols make maps simple and easy to understand.
• They can represent roads, railway lines, buildings, rivers, boundaries and other features.
• The Survey of India uses a standard set of symbols for maps of India.

Topic 7: Globe

• A globe is a spherical model of the Earth.
• It represents the shape of the Earth more naturally than a flat map.
• A globe can show continents, oceans, countries and the imaginary lines used to locate places.

Topic 8: Coordinates

• Coordinates help us identify the precise location of a place.
• The two coordinates are latitude and longitude.
• The intersection of a particular latitude and longitude identifies a specific location.

Topic 9: Latitudes

• Latitudes measure distance north or south of the Equator.
• Parallels of latitude are imaginary circles running east-west.
• The Equator is 0° latitude.
• The North Pole is 90°N.
• The South Pole is 90°S.
• Parallels become smaller towards the poles.

Topic 10: Latitudes and Climate

• Latitude has an important relationship with climate.
• Places near the Equator generally receive more direct sunlight and are warmer.
• Places towards the poles are generally colder.

Topic 11: Longitudes

• Longitudes are imaginary half-circles running from the North Pole to the South Pole.
• They measure distance east or west of the Prime Meridian.
• The Prime Meridian is 0° longitude.
• Longitudes are measured up to 180° east and 180° west.
• 180°E and 180°W represent the same longitude.

Topic 12: Prime Meridian

• The Prime Meridian is the reference line for measuring longitude.
• It is marked 0° longitude.
• It passes through Greenwich in London.
• It divides the Earth into the Eastern and Western Hemispheres.

Topic 13: Hemispheres

• The Equator divides the Earth into the Northern and Southern Hemispheres.
• The Prime Meridian divides the Earth into the Eastern and Western Hemispheres.
• A hemisphere means one half of the Earth.

Topic 14: Latitude and Longitude Grid

• Latitudes and longitudes together form a grid on the globe.
• This grid is used to locate places accurately.
• Every location can be identified using its latitude and longitude.

Topic 15: Ancient Indian Knowledge

• Ancient Indian astronomers had knowledge of latitude and longitude.
• Ujjayini was an important centre of astronomy.
• The Ujjayini meridian was known as madhya rekhā.
• It was used as a reference in ancient Indian astronomical calculations.

Topic 16: Location of India

• India extends approximately from 8°N to 37°N latitudes.
• India extends approximately from 68°E to 97°E longitudes.
• India lies in the Northern and Eastern Hemispheres.

Topic 17: Longitude and Time

• The Earth rotates through 360° in 24 hours.
• Therefore, it rotates through 15° in one hour.
• Thus, a difference of 15° longitude corresponds approximately to a one-hour difference in local time.
• Places towards the east have later local time.
• Places towards the west have earlier local time.

Topic 18: Local Time

• Local time depends on the longitude of a place.
• Different longitudes have different local times.
• Using different local times throughout a country can create confusion.

Topic 19: Standard Time

• A country generally selects a particular meridian as a reference for its standard time.
• India follows Indian Standard Time (IST).
• IST is 5 hours 30 minutes ahead of GMT.

Topic 20: Time Zones

• A time zone is an area where the same standard time is followed.
• Time zones are broadly based on 15° intervals of longitude.
• Actual time-zone boundaries may follow the political boundaries of countries.
• Large countries may have several time zones.

Topic 21: International Date Line

• The International Date Line lies approximately at 180° longitude.
• It lies opposite the Prime Meridian.
• Crossing the International Date Line changes the date by one day.
• When crossed eastward, one day is subtracted.
• When crossed westward, one day is added.
• The line is not perfectly straight because it bends around some countries and islands.

Quick Facts

• Equator: 0° latitude
• North Pole: 90°N
• South Pole: 90°S
• Prime Meridian: 0° longitude
• Maximum Longitude: 180°E or 180°W
• India: Approximately 8°N–37°N and 68°E–97°E
• Earth's Rotation: 360° in 24 hours
• Time Difference: 15° longitude ≈ 1 hour
• IST: GMT + 5 hours 30 minutes
• International Date Line: Approximately 180° longitude

Locating Places on the Earth

Locating Places on the Earth

Maps

A map is a representation or drawing of an area of the Earth's surface as seen from above. Maps help us locate places and understand different features of the Earth.

• Maps can represent a small area such as a village or a large area such as a country or the whole world.
• Maps are useful for finding locations, directions, distances and geographical features.
• An atlas is a collection of maps in the form of a book.
• Maps may show natural features, political boundaries or information related to a particular theme.

Types of Maps

• Physical Maps: Show natural features such as mountains, rivers, oceans and plains.
• Political Maps: Show countries, states, boundaries, cities and other political features.
• Thematic Maps: Show information related to a particular theme or topic.

Components of a Map

The three main components of a map are distance, direction and symbols.

• Distance: Tells us how far one place is from another.
• Direction: Helps us identify the position of one place in relation to another.
• Symbols: Represent different geographical and human-made features on a map.

Scale

Scale shows the relationship between a distance shown on a map and the actual distance on the ground.

• Scale allows a very large area to be represented on a small map.
• For example, if 1 cm on a map represents 500 m on the ground, the scale is 1 cm = 500 m.
• Scale is important for calculating actual distances from a map.

Directions

• The four main or cardinal directions are North, East, South and West.
• The intermediate directions are Northeast, Southeast, Southwest and Northwest.
• Directions help us describe the position of one place in relation to another.

Map Symbols

Symbols are conventional signs used on maps to represent different features.

• Symbols make maps simple and easy to understand.
• They can represent roads, railway lines, rivers, buildings, boundaries and other features.
• The Survey of India has fixed a set of symbols for maps of India and parts of India.

Globe

A globe is a spherical model of the Earth. It represents the Earth's shape more naturally than a flat map.

• A globe shows the continents, oceans and other major features of the Earth.
• It also helps us understand the position of the Equator, latitudes and longitudes.
• A globe is useful for understanding the Earth as a whole.

Coordinates

Coordinates are used to identify the precise location of a place on the Earth.

• The two coordinates are latitude and longitude.
• Latitude tells us how far north or south a place is from the Equator.
• Longitude tells us how far east or west a place is from the Prime Meridian.
• The intersection of a particular latitude and longitude helps identify a specific location.

Latitudes

Latitude is the measure of the distance of a place north or south of the Equator.

• Latitudes are imaginary lines drawn around the Earth from east to west.
• They are also called parallels of latitude because they are parallel to one another.
• The Equator is the longest parallel of latitude.
• The Equator represents 0° latitude.
• Latitudes are measured from 0° to 90° towards the north or south.
• The North Pole is at 90°N.
• The South Pole is at 90°S.
• The length of the parallels decreases as they approach the poles.

Latitudes and Climate

Latitude has an important relationship with the climate of a place.

• Places near the Equator generally receive more direct sunlight and are warmer.
• Places towards the North and South Poles are generally colder.
• Thus, latitude is an important factor in understanding differences in climate.

Longitudes

Longitude is the measure of the distance of a place east or west of the Prime Meridian.

• Lines of longitude are imaginary half-circles running from the North Pole to the South Pole.
• They are also called meridians of longitude.
• All meridians meet at the North Pole and South Pole.
• The Prime Meridian represents 0° longitude.
• Longitudes are measured from 0° to 180° towards the east and west.
• 180°E and 180°W represent the same longitude.

Prime Meridian

The Prime Meridian is the reference meridian from which longitudes are measured.

• It is marked as 0° longitude.
• It passes through Greenwich in London, England.
• It is also called the Greenwich Meridian.
• It divides the Earth into the Eastern and Western Hemispheres.

Equator

The Equator is an imaginary circle around the middle of the Earth and represents 0° latitude.

• It is the longest parallel of latitude.
• It divides the Earth into the Northern Hemisphere and Southern Hemisphere.
• All other parallels of latitude are smaller than the Equator.

Hemispheres

A hemisphere means one half of the Earth.

• The Equator divides the Earth into the Northern Hemisphere and Southern Hemisphere.
• The Prime Meridian divides the Earth into the Eastern Hemisphere and Western Hemisphere.
• A place can belong to two hemispheres at the same time, such as the Northern and Eastern Hemispheres.

Latitude and Longitude Grid

Latitudes and longitudes together form a network of imaginary lines called a grid or grid lines.

• Parallels of latitude run from east to west.
• Meridians of longitude run from north to south, from pole to pole.
• The grid helps us locate any place precisely on the Earth.
• The approximate latitude and longitude of a place can be found using a globe or atlas.

Ancient Indian Knowledge of Latitude and Longitude

Ancient Indian astronomers were aware of the concepts of latitude, longitude and the need for a reference or prime meridian.

• Ujjayini, present-day Ujjain, was a reputed centre of astronomy.
• The ancient Indian prime meridian was called madhya rekhā, meaning the “middle line”.
• The Ujjayini meridian passed through Ujjayini.
• The Ujjayini meridian became a reference for calculations in Indian astronomical texts.
• Varāhamihira was a famous astronomer who lived and worked at Ujjayini about 1,500 years ago.

Location of India

India can be located precisely with the help of its latitudes and longitudes.

• India extends approximately from 8°N to 37°N latitudes.
• India extends approximately from 68°E to 97°E longitudes.
• India lies in the Northern Hemisphere.
• India also lies in the Eastern Hemisphere.

Earth's Rotation and Time

The Earth rotates on its axis, and this rotation causes differences in local time at different longitudes.

• The Earth completes one complete rotation of 360° in 24 hours.
• Therefore, the Earth rotates through 15° in one hour.
• Thus, a difference of 15° longitude corresponds approximately to a difference of one hour in local time.
• A difference of 1° longitude corresponds approximately to 4 minutes of time.

Longitude and Local Time

Local time at a place is related to its longitude.

• Places located towards the east have a later local time.
• Places located towards the west have an earlier local time.
• For every 15° difference in longitude, the local time differs by approximately one hour.
• For example, if it is noon at the Prime Meridian, the local time at 15°E is approximately 1 p.m.
• At 15°W, the local time would be approximately 11 a.m.

Local Time

Local time is the time calculated according to the longitude of a particular place.

• Different places can have different local times because they lie at different longitudes.
• As the Earth rotates from west to east, places to the east experience sunrise and later times earlier than places to the west.
• Using separate local times for every place in a large country would be inconvenient.

Standard Time

Standard time is an officially adopted time used throughout a country or a defined region.

• A country selects a particular meridian as the reference for its standard time.
• Standard time avoids confusion caused by different local times.
• India follows a single standard time called Indian Standard Time (IST).
• IST is based on the standard meridian of India.
• IST is 5 hours 30 minutes ahead of GMT.

Time Zones

A time zone is a geographical region in which the same standard time is followed.

• The Earth is divided broadly into time zones based on differences in longitude.
• A difference of approximately 15° longitude corresponds to one hour.
• Time-zone boundaries do not always exactly follow meridians of longitude.
• They may be adjusted to follow international or political boundaries.
• Large countries may have several time zones.
• The USA has six time zones.
• Russia has eleven time zones.

International Date Line

The International Date Line is an imaginary line located approximately at 180° longitude, opposite the Prime Meridian.

• The International Date Line is associated with a change of date.
• When the line is crossed while travelling eastward, one day is subtracted.
• When the line is crossed while travelling westward, one day is added.
• The line is approximately at 180° longitude rather than exactly following a straight meridian.
• It deviates in some places to avoid dividing countries into two different dates.

Important Differences

Latitude	Longitude
Measures distance north or south of the Equator.	Measures distance east or west of the Prime Meridian.
Latitudes are parallel to the Equator.	Longitudes run from pole to pole.
The Equator is the 0° latitude.	The Prime Meridian is the 0° longitude.

Map	Globe
A map is a flat representation of an area.	A globe is a spherical model of the Earth.
It can show a small or large area in considerable detail.	It represents the Earth's overall spherical form.

Local Time	Standard Time
Depends on the longitude of a particular place.	Officially adopted for a country or region.
May differ from place to place.	Provides a common time for the relevant region.

Parallel of Latitude	Meridian of Longitude
Runs from east to west.	Runs from the North Pole to the South Pole.
Parallel to the Equator.	All meridians meet at the poles.
The Equator is the longest parallel.	The Prime Meridian is the reference meridian.

Important Numerical Relationships

• 360° rotation of Earth = 24 hours
• 15° longitude = 1 hour
• 1° longitude = 4 minutes
• Eastward movement = Add time
• Westward movement = Subtract time
• IST = GMT + 5 hours 30 minutes

Important Facts to Remember

• The Equator is the longest parallel of latitude.
• The South Pole is at 90°S.
• The Prime Meridian passes through Greenwich.
• Latitudes and longitudes together create a grid.
• Coordinates help us locate a place precisely.
• India follows Indian Standard Time.
• The International Date Line is approximately at 180° longitude.
• The date changes when the International Date Line is crossed.

Locating Places on the Earth

Chapter 1. Locating Places on the Earth

Assignment

A. Fill in the Blanks

1. The three main components of a map are __________, __________ and __________.
2. A book or collection of maps is called an __________.
3. The __________ is the longest parallel of latitude.
4. The Equator represents __________° latitude.
5. The North Pole is located at __________°N.
6. The South Pole is located at __________°S.
7. The Prime Meridian represents __________° longitude.
8. The Prime Meridian passes through __________ in London.
9. Latitude and longitude together are called the __________ of a place.
10. India follows __________ Standard Time.
11. IST is __________ hours and __________ minutes ahead of GMT.
12. The International Date Line lies approximately at __________° longitude.

B. Multiple Choice Questions

1. Which of the following is a component of a map?
   1. Distance
   2. Direction
   3. Symbols
   4. All of these
2. Which is the longest parallel of latitude?
   1. Prime Meridian
   2. Equator
   3. Tropic of Cancer
   4. Arctic Circle
3. What is the latitude of the South Pole?
   1. 0°
   2. 90°N
   3. 90°S
   4. 180°
4. What does longitude measure?
   1. Distance north or south of the Equator
   2. Distance east or west of the Prime Meridian
   3. Distance from the poles
   4. Height above sea level
5. Which line represents 0° longitude?
   1. Equator
   2. Prime Meridian
   3. Tropic of Cancer
   4. International Date Line
6. Which two things together help us locate a place precisely?
   1. Distance and direction
   2. Latitude and longitude
   3. Map and atlas
   4. Equator and poles
7. How much time difference is approximately caused by 15° of longitude?
   1. 15 minutes
   2. 30 minutes
   3. 1 hour
   4. 2 hours
8. Which direction has a later local time?
   1. West
   2. East
   3. North
   4. South
9. What is the standard time followed in India?
   1. GMT
   2. IST
   3. UTC
   4. Ujjayini Time
10. Approximately where is the International Date Line located?
    1. 0° longitude
    2. 90° longitude
    3. 180° longitude
    4. 360° longitude

C. True or False

1. All parallels of latitude have the same length.
2. The Equator is a parallel of latitude.
3. The South Pole has a latitude of 90°S.
4. The Prime Meridian represents 0° longitude.
5. All meridians of longitude are parallel to one another.
6. Latitude and longitude together help locate a place precisely.
7. Local time becomes later as we move westward.
8. India follows Indian Standard Time.
9. Time-zone boundaries are always exactly the same as meridians of longitude.
10. Crossing the International Date Line can change the date.

D. Match the Following

Column A	Column B
1. Equator	a. 0° Longitude
2. Prime Meridian	b. Approximately 180° Longitude
3. North Pole	c. 0° Latitude
4. South Pole	d. 90°N
5. International Date Line	e. 90°S

E. Answer in One Sentence

1. What is a map?
2. What is an atlas?
3. What is a globe?
4. What is scale?
5. What are coordinates?
6. What is latitude?
7. What is longitude?
8. What is the Equator?
9. What is the Prime Meridian?
10. What is local time?
11. What is standard time?
12. What is a time zone?
13. What is the International Date Line?

F. Short Answer Questions

1. What are the three main components of a map? Explain each briefly.
2. What is the difference between a physical map and a political map?
3. Why are symbols used on maps?
4. What is the difference between a map and a globe?
5. How do latitude and longitude help us locate a place?
6. What are parallels of latitude?
7. What are meridians of longitude?
8. Why is the Equator important?
9. Why is the Prime Meridian important?
10. How are the Eastern and Western Hemispheres formed?
11. Why do places at different longitudes have different local times?
12. Why do countries adopt a standard time?
13. Why do large countries sometimes have more than one time zone?
14. What is the importance of the International Date Line?

G. Long Answer Questions

1. Explain the different types of maps and state the purpose of each.
2. Explain latitude and longitude with their important features.
3. Explain how the grid of latitudes and longitudes helps in locating places.
4. Explain the relationship between the Earth's rotation, longitude and local time.
5. Explain the difference between local time and standard time with suitable examples.
6. Explain the International Date Line and describe what happens when it is crossed.
7. Describe the contribution of ancient Indian astronomers to the understanding of latitude and longitude.

H. Application-Based Questions

1. A city lies at 30°E longitude and another city lies at 45°E longitude.
   What would be the approximate difference in their local times?
2. If it is 12:00 noon at the Prime Meridian, what would be the approximate local time at 30°E?
3. If it is 12:00 noon at the Prime Meridian, what would be the approximate local time at 30°W?
4. Two cities have almost the same longitude, 77°E. What would you expect about the difference in their local times?
5. A traveller crosses the International Date Line while travelling westward. What happens to the date?
6. A student says, “The Equator and the Prime Meridian are both longitudes.” Is the statement correct? Give a reason.

I. Map and Globe Based Questions

1. Mark the Equator on a blank outline map of the world.
2. Mark the Prime Meridian on a blank outline map of the world.
3. Mark the Northern, Southern, Eastern and Western Hemispheres.
4. Locate India using its approximate latitude and longitude.
5. Mark the North Pole and South Pole on a globe or world map.
6. Draw a simple diagram showing parallels of latitude and meridians of longitude.

J. Think and Answer

1. Why would it be difficult if every town and city in a country followed its own local time?
2. Why are the lines of longitude important for calculating time?
3. Why is the International Date Line not perfectly straight?
4. Why does the length of parallels of latitude decrease towards the poles?
5. Why are coordinates more useful than simply giving the name of a place?